987656329domain: NAppears in sequencesLargest n-digit square with property that digits alternate in parity, or 0 if no such number exists.at n=8A068881Number of nX6 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 0 and 1 0 1 vertically.at n=9A208037